closedcaption: Move common parsers into a separate file

video/closedcaption/src/lib.rs

@@ -40,6 +40,7 @@ mod cea608tott;
 mod line_reader;
 mod mcc_enc;
 mod mcc_parse;
+mod parser_utils;
 mod scc_enc;
 mod scc_parse;
 mod tttocea608;

video/closedcaption/src/parser_utils.rs

@@ -0,0 +1,90 @@
+// Copyright (C) 2020 Sebastian Dröge <sebastian@centricular.com>
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the
+// Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
+// Boston, MA 02110-1335, USA.
+
+use nom::IResult;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct TimeCode {
+    pub hours: u32,
+    pub minutes: u32,
+    pub seconds: u32,
+    pub frames: u32,
+    pub drop_frame: bool,
+}
+
+/// Parser for parsing a run of ASCII, decimal digits and converting them into a `u32`
+pub fn digits(s: &[u8]) -> IResult<&[u8], u32> {
+    use nom::bytes::complete::take_while;
+    use nom::character::is_digit;
+    use nom::combinator::map_res;
+
+    map_res(
+        map_res(take_while(is_digit), |s: &[u8]| std::str::from_utf8(s)),
+        |s: &str| s.parse::<u32>(),
+    )(s)
+}
+
+/// Parser for a run of decimal digits, that converts them into a `u32` and checks if the result is
+/// in the allowed range.
+pub fn digits_range<R: std::ops::RangeBounds<u32>>(
+    range: R,
+) -> impl FnMut(&[u8]) -> IResult<&[u8], u32> {
+    use nom::combinator::verify;
+    use nom::error::context;
+
+    move |s: &[u8]| context("digits out of range", verify(digits, |v| range.contains(v)))(s)
+}
+
+/// Parser for a timecode in the form `hh:mm:ss:fs`
+pub fn timecode(s: &[u8]) -> IResult<&[u8], TimeCode> {
+    use nom::character::complete::{char, one_of};
+    use nom::combinator::map;
+    use nom::error::context;
+    use nom::sequence::tuple;
+
+    context(
+        "invalid timecode",
+        map(
+            tuple((
+                digits,
+                char(':'),
+                digits_range(0..60),
+                char(':'),
+                digits_range(0..60),
+                one_of(":.;,"),
+                digits,
+            )),
+            |(hours, _, minutes, _, seconds, sep, frames)| TimeCode {
+                hours,
+                minutes,
+                seconds,
+                frames,
+                drop_frame: sep == ';' || sep == ',',
+            },
+        ),
+    )(s)
+}
+
+/// Parser that checks for EOF and optionally `\n` or `\r\n` before EOF
+pub fn end_of_line(s: &[u8]) -> IResult<&[u8], ()> {
+    use nom::branch::alt;
+    use nom::bytes::complete::tag;
+    use nom::combinator::{eof, map, opt};
+    use nom::sequence::pair;
+
+    map(pair(opt(alt((tag("\r\n"), tag("\n")))), eof), |_| ())(s)
+}

video/closedcaption/src/scc_parse/imp.rs

@@ -23,8 +23,9 @@ use gst::subclass::prelude::*;
 
 use std::sync::{Mutex, MutexGuard};
 
-use super::parser::{SccLine, SccParser, TimeCode};
+use super::parser::{SccLine, SccParser};
 use crate::line_reader::LineReader;
+use crate::parser_utils::TimeCode;
 
 lazy_static! {
     static ref CAT: gst::DebugCategory = {

video/closedcaption/src/scc_parse/parser.rs

@@ -16,17 +16,9 @@
 // Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
 // Boston, MA 02110-1335, USA.
 
+use crate::parser_utils::{end_of_line, timecode, TimeCode};
 use nom::IResult;
 
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct TimeCode {
-    pub hours: u32,
-    pub minutes: u32,
-    pub seconds: u32,
-    pub frames: u32,
-    pub drop_frame: bool,
-}
-
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum SccLine {
     Header,
@@ -46,69 +38,6 @@ pub struct SccParser {
     state: State,
 }
 
-/// Parser for parsing a run of ASCII, decimal digits and converting them into a `u32`
-fn digits(s: &[u8]) -> IResult<&[u8], u32> {
-    use nom::bytes::complete::take_while;
-    use nom::character::is_digit;
-    use nom::combinator::map_res;
-
-    map_res(
-        map_res(take_while(is_digit), |s: &[u8]| std::str::from_utf8(s)),
-        |s: &str| s.parse::<u32>(),
-    )(s)
-}
-
-/// Parser for a run of decimal digits, that converts them into a `u32` and checks if the result is
-/// in the allowed range.
-fn digits_range<R: std::ops::RangeBounds<u32>>(
-    range: R,
-) -> impl FnMut(&[u8]) -> IResult<&[u8], u32> {
-    use nom::combinator::verify;
-    use nom::error::context;
-
-    move |s: &[u8]| context("digits out of range", verify(digits, |v| range.contains(v)))(s)
-}
-
-/// Parser for a timecode in the form `hh:mm:ss:fs`
-fn timecode(s: &[u8]) -> IResult<&[u8], TimeCode> {
-    use nom::character::complete::{char, one_of};
-    use nom::combinator::map;
-    use nom::error::context;
-    use nom::sequence::tuple;
-
-    context(
-        "invalid timecode",
-        map(
-            tuple((
-                digits,
-                char(':'),
-                digits_range(0..60),
-                char(':'),
-                digits_range(0..60),
-                one_of(":.;,"),
-                digits,
-            )),
-            |(hours, _, minutes, _, seconds, sep, frames)| TimeCode {
-                hours,
-                minutes,
-                seconds,
-                frames,
-                drop_frame: sep == ';' || sep == ',',
-            },
-        ),
-    )(s)
-}
-
-/// Parser that checks for EOF and optionally `\n` or `\r\n` before EOF
-fn end_of_line(s: &[u8]) -> IResult<&[u8], ()> {
-    use nom::branch::alt;
-    use nom::bytes::complete::tag;
-    use nom::combinator::{eof, map, opt};
-    use nom::sequence::pair;
-
-    map(pair(opt(alt((tag("\r\n"), tag("\n")))), eof), |_| ())(s)
-}
-
 /// Parser for the SCC header
 fn header(s: &[u8]) -> IResult<&[u8], SccLine> {
     use nom::bytes::complete::tag;